The printability of gravure ink mainly considers the following three aspects:
(1) When ink is transferred from the ink fountain to the layout, the rheological properties of the ink should be considered. Poor rheological properties will cause the ink to fail to fill the screen pattern, or overflow ink, or even transfer poorly through external agitation.
(2) The position and pressure of the squeegee are not suitable, which can cause scratches, stains, and affect the quality of printed products. The angle between the contact point between the blade and the roller is usually 45°. If the blade is perpendicular to the roller, the ink in the dot will be pressed. If the pressure is too large or too small, the fluidity of the ink will be damaged.
(3) The embossing force and embossing position applied to the ink dots. The embossing position should be a quarter of the diameter of the roller at the point where the squeegee is connected to the roller. In advance of imprinting, the dots of the ink have not yet deformed normally. Both can make ink flow uncomfortable. The printing pressure should be appropriate. If the pressure is too high, the ink may overflow and the embossing will spread and deform; if the pressure is too small, the ink transfer may not be sufficient, resulting in too thin an ink layer. Both govern the thinness of the ink layer, drying speed, and inking effect.
In order to produce good and bright printed products, it is necessary to prevent the powder from showing through, poor drying, poor adhesion, and overcome the problems caused by the unevenness of the paper and the hardness of the plastic film.